Compiled by A. Michael Noll (with personal knowledge and an admitted bias toward speech research and computer graphics) and with sagacious comments from several Bell Telephone Laboratories colleagues.

Bell Telephone Laboratories, Inc. (BTL) was formed in 1925 and existed until the breakup of the Bell System on January 1, 1984. Only this period of nearly six decades is included here.

Innovations and discoveries were chosen to be significant new directions and not just incremental advances. However, a few “fascinating” ones, such as the “dunking bird,” have been included.

Tens of thousands of engineers, scientists, technicians, and others worked at Bell Telephone Laboratories, and all contributed in their own way to the overall accomplishments of the organization. Only a small few are listed here though.

On many of the larger development projects and systems, large engineering teams were involved, and accordingly individuals are not named.